In the applications of high bandwidth and high data transfer rate, Long Term Evolution Advanced (LTE-A) is expected to meet the demands for high transmission bandwidths in the future due to its various advantages, such as reduced transmission delay, increased data transfer rate, increased system throughput, and efficient use of spectrum and the like.
In order to achieve high transmission bandwidth, the use of a large segment of bandwidth is a direct way for improving the transmission bandwidth, but to find a large segment of unused bandwidth in the wireless network is not easy. Therefore, Carrier Aggregation (CA) technology is introduced into LTE-A, which is based on the existing carrier in Long Term Evolution (LTE), and a plurality of carriers are further aggregated to form a carrier with a larger bandwidth in order to meet the demand for high transmission bandwidth.
However, LTE-A specifies that a home base station (or a picocell base station) can have only one cell, and the home base station can only register with a Mobility Management Entity (MME) or a core network with the globally unique cell identity (CID) of the cell, so the home base station is unable to support the carrier aggregation technology.
Thus, under the existing framework of LTE-A, in order to allow a home base station to have a plurality of cells and thus support CA, the home base station can only register one of the plurality of cells, the MME will not know the existence of the other cells.
Thus, when a user equipment (UE) wishes to transfer from its eNB to an unregistered cell of the home base station, the MME will not be able to look up the routing information and cannot forward the handover request to the home base station. Furthermore, the home base station cannot correctly identify the cell to which the UE has transferred.
Therefore, there is a need for a solution that overcomes the aforementioned prior-art issues.